diff options
Diffstat (limited to 'drivers/oprofile/oprofilefs.c')
| -rw-r--r-- | drivers/oprofile/oprofilefs.c | 93 |
1 files changed, 48 insertions, 45 deletions
diff --git a/drivers/oprofile/oprofilefs.c b/drivers/oprofile/oprofilefs.c index e9ff6f7770b..3f493459378 100644 --- a/drivers/oprofile/oprofilefs.c +++ b/drivers/oprofile/oprofilefs.c @@ -21,7 +21,7 @@ #define OPROFILEFS_MAGIC 0x6f70726f -DEFINE_SPINLOCK(oprofilefs_lock); +DEFINE_RAW_SPINLOCK(oprofilefs_lock); static struct inode *oprofilefs_get_inode(struct super_block *sb, int mode) { @@ -60,6 +60,13 @@ ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t cou } +/* + * Note: If oprofilefs_ulong_from_user() returns 0, then *val remains + * unchanged and might be uninitialized. This follows write syscall + * implementation when count is zero: "If count is zero ... [and if] + * no errors are detected, 0 will be returned without causing any + * other effect." (man 2 write) + */ int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count) { char tmpbuf[TMPBUFSIZE]; @@ -76,10 +83,10 @@ int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_ if (copy_from_user(tmpbuf, buf, count)) return -EFAULT; - spin_lock_irqsave(&oprofilefs_lock, flags); + raw_spin_lock_irqsave(&oprofilefs_lock, flags); *val = simple_strtoul(tmpbuf, NULL, 0); - spin_unlock_irqrestore(&oprofilefs_lock, flags); - return 0; + raw_spin_unlock_irqrestore(&oprofilefs_lock, flags); + return count; } @@ -99,7 +106,7 @@ static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_ return -EINVAL; retval = oprofilefs_ulong_from_user(&value, buf, count); - if (retval) + if (retval <= 0) return retval; retval = oprofile_set_ulong(file->private_data, value); @@ -110,63 +117,59 @@ static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_ } -static int default_open(struct inode *inode, struct file *filp) -{ - if (inode->i_private) - filp->private_data = inode->i_private; - return 0; -} - - static const struct file_operations ulong_fops = { .read = ulong_read_file, .write = ulong_write_file, - .open = default_open, + .open = simple_open, .llseek = default_llseek, }; static const struct file_operations ulong_ro_fops = { .read = ulong_read_file, - .open = default_open, + .open = simple_open, .llseek = default_llseek, }; -static int __oprofilefs_create_file(struct super_block *sb, - struct dentry *root, char const *name, const struct file_operations *fops, - int perm, void *priv) +static int __oprofilefs_create_file(struct dentry *root, char const *name, + const struct file_operations *fops, int perm, void *priv) { struct dentry *dentry; struct inode *inode; + mutex_lock(&root->d_inode->i_mutex); dentry = d_alloc_name(root, name); - if (!dentry) + if (!dentry) { + mutex_unlock(&root->d_inode->i_mutex); return -ENOMEM; - inode = oprofilefs_get_inode(sb, S_IFREG | perm); + } + inode = oprofilefs_get_inode(root->d_sb, S_IFREG | perm); if (!inode) { dput(dentry); + mutex_unlock(&root->d_inode->i_mutex); return -ENOMEM; } inode->i_fop = fops; + inode->i_private = priv; d_add(dentry, inode); - dentry->d_inode->i_private = priv; + mutex_unlock(&root->d_inode->i_mutex); return 0; } -int oprofilefs_create_ulong(struct super_block *sb, struct dentry *root, +int oprofilefs_create_ulong(struct dentry *root, char const *name, unsigned long *val) { - return __oprofilefs_create_file(sb, root, name, + return __oprofilefs_create_file(root, name, &ulong_fops, 0644, val); } -int oprofilefs_create_ro_ulong(struct super_block *sb, struct dentry *root, +int oprofilefs_create_ro_ulong(struct dentry *root, char const *name, unsigned long *val) { - return __oprofilefs_create_file(sb, root, name, + return __oprofilefs_create_file(root, name, &ulong_ro_fops, 0444, val); } @@ -180,50 +183,54 @@ static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t coun static const struct file_operations atomic_ro_fops = { .read = atomic_read_file, - .open = default_open, + .open = simple_open, .llseek = default_llseek, }; -int oprofilefs_create_ro_atomic(struct super_block *sb, struct dentry *root, +int oprofilefs_create_ro_atomic(struct dentry *root, char const *name, atomic_t *val) { - return __oprofilefs_create_file(sb, root, name, + return __oprofilefs_create_file(root, name, &atomic_ro_fops, 0444, val); } -int oprofilefs_create_file(struct super_block *sb, struct dentry *root, +int oprofilefs_create_file(struct dentry *root, char const *name, const struct file_operations *fops) { - return __oprofilefs_create_file(sb, root, name, fops, 0644, NULL); + return __oprofilefs_create_file(root, name, fops, 0644, NULL); } -int oprofilefs_create_file_perm(struct super_block *sb, struct dentry *root, +int oprofilefs_create_file_perm(struct dentry *root, char const *name, const struct file_operations *fops, int perm) { - return __oprofilefs_create_file(sb, root, name, fops, perm, NULL); + return __oprofilefs_create_file(root, name, fops, perm, NULL); } -struct dentry *oprofilefs_mkdir(struct super_block *sb, - struct dentry *root, char const *name) +struct dentry *oprofilefs_mkdir(struct dentry *parent, char const *name) { struct dentry *dentry; struct inode *inode; - dentry = d_alloc_name(root, name); - if (!dentry) + mutex_lock(&parent->d_inode->i_mutex); + dentry = d_alloc_name(parent, name); + if (!dentry) { + mutex_unlock(&parent->d_inode->i_mutex); return NULL; - inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); + } + inode = oprofilefs_get_inode(parent->d_sb, S_IFDIR | 0755); if (!inode) { dput(dentry); + mutex_unlock(&parent->d_inode->i_mutex); return NULL; } inode->i_op = &simple_dir_inode_operations; inode->i_fop = &simple_dir_operations; d_add(dentry, inode); + mutex_unlock(&parent->d_inode->i_mutex); return dentry; } @@ -231,7 +238,6 @@ struct dentry *oprofilefs_mkdir(struct super_block *sb, static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent) { struct inode *root_inode; - struct dentry *root_dentry; sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; @@ -244,15 +250,11 @@ static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent) return -ENOMEM; root_inode->i_op = &simple_dir_inode_operations; root_inode->i_fop = &simple_dir_operations; - root_dentry = d_alloc_root(root_inode); - if (!root_dentry) { - iput(root_inode); + sb->s_root = d_make_root(root_inode); + if (!sb->s_root) return -ENOMEM; - } - - sb->s_root = root_dentry; - oprofile_create_files(sb, root_dentry); + oprofile_create_files(sb->s_root); // FIXME: verify kill_litter_super removes our dentries return 0; @@ -272,6 +274,7 @@ static struct file_system_type oprofilefs_type = { .mount = oprofilefs_mount, .kill_sb = kill_litter_super, }; +MODULE_ALIAS_FS("oprofilefs"); int __init oprofilefs_register(void) |